狐表软件是什么(给狐表的递归教程加上死循环判断)

1思路说明

基于官方的递归文档案例，适当修改代码，可以判断出递归死循环的路线，及时停止（思路来自最新版Bom目录树玩法）

1. 每条分支，都不应该重复利用主键

2. 不同分支，可以重复利用主键，毕竟bom会重复利用

所以：在每条分支，都用一个空白的字典，记录主键，保持不重复。如果重复，就遍历出来展示告知用户

2递归开始的代码：

Dim tr As WinForm.TreeView = e.Form.Controls("TreeView1")Dim nd As WinForm.TreeNodeDim dt As DataTable = DataTables("表A")tr.StopRedraw()tr.Nodes.Cleartr.Nodes.Add("全部")Dim dgDic As New Dictionary(of String,String)'递归记录,防止死循环For Each dr As DataRow In dt.datarows    If dr.IsNull("父键") Then        nd = tr.Nodes.Add(dr("键"),dr("标题"))        Functions.Execute("AddChildren",nd,dt,dgDic)    End If    dgDic.Clear '一条递归用一套记录Nexttr.ResumeRedraw()

3内部函数：

Dim nd As WinForm.TreeNode = args(0)Dim dt As DataTable = args(1)Dim dgDic As Dictionary(of String,String) = args(2)Dim drs As  List(of DataRow)drs = dt.Select("[父键] = '" & nd.name & "'")For Each dr As DataRow In drs    Dim cd As Winform.TreeNode = nd.Nodes.Add(dr("键"),dr("标题"))    If dgDic.ContainsKey(dr("键")) = False Then        dgDic.Add(dr("键"),dr("标题"))        Functions.Execute("AddChildren",cd,dt,dgDic)    Else        Dim s As String ="出现死循环:"        For Each key As String In dgDic.Keys            If key = dr("键") Then                s &= "[" & dgDic(key) & "]→"            Else                s &=dgDic(key) & "→"            End If                    Next        s &=dr("标题") & "→[" & dgDic(dr("键")) & "]"        MessageBox.Show(s)    End IfNext